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Re: Geo vs Astro chemistry Errata

Hello again,

I reread these musings myself and seem to always miss a few things.  Thanks for
keeping me straight.  I was relying on some "ancient geology" from my college
days where the fact was disclosed that "iron is never(sic) found in true native
state (Fe or Fe2). There have been reports of small nodules/ viens of iron which
have pooled out of  basalts which radidly form iron oxide."  

When I wrote the earlier post, I believed that native iron could not long esist
in the crust as it was so reactive that it would weather out (oxidize).  After
some additional research, I accept that native iron can and does exist, at least
for a brief period.  I was speaking from a perspective that a predominately iron
specimen would have oxidixed and not be "native" Further,when native nickel is
found, its iron content is ordinarily small and likely in the form of an oxide
or sulphide  etc.  That is true most of the time  but not all the time.  I
retract that you will never find unoxidized iron in the crust and I reiterate
that natural iron will always have a nickel content-- ranging from 2%-76% it
seems.  A minor point  but I believe I understand that the terrestrial iron when
found, is not natively pure like gold or copper can be.  The distinction between
alloy and compound blurs. The iron and nickel form molecules,  but those bonds
are week and easily broken during the heat of smelting.  Then again, the
meteoric irons are also actual nickel iron compounds which could also be
considered an alloy.  Any additional thoughts?

I knew  a little about the existance of josephinite but did mention it in my
post.  Josephinite has been determined to be the same as the formerly described
awaruite (Ni3Fe). It is a naturally occuring alloy mineral containing elemental
iron which fits the definition of mineral.  I do not know if it is directly from
the mantle via extruded plutonic pools of molten iron or if they are from
crustal subducted iron ores which were naturally smelted.  The occurance with
basalt tends to favor a crustal origin but the high nickel content seems to
favor something more of a mantle origin.  (Incidentally there is also an native
iridium-iron alloy which has has a very high specific gravity, 22.4--nearly
double that of lead.)  I have recovered some material which contains small loose
beads (3-6mm) of magnetically attractive metal,  which I discounted it as a slag
product-- I need to relook that.

For clarification and/or retraction:
Terrestrial natural iron is rare, in metalic form(native), and will always
contain a nickel component .  
Native iron-nickel masses beyond nugget form have not been identified .
Iron oxidizes so rapidly that it is rarely found in elemental form on the
earth's surface. 
"Nickelless" Iron is signature for an artifact of human origins.
Native nickel has been found in small crystilline masses but still associated
with platinum,silver, etc--as I understand


Metalic iron specimens in the earth's crust are very rare and command a hefty
price from mineral collectors when available. Excerpts as follows:
"Hungtukun Massif, Taymyr Peninsula, Krasnoyarsk region, Siberia, Russia 
 It consists of a basalt host rock in which a  substantial amount of native Iron
has formed. The important aspect is that it is not of meteoric origin. This is
native Iron that has formed through complex chemical processes in the Earth's
crust! ..... It has a moderate silvery-white coloration and the standard
metallic luster. The polished face has been coated with a clear lacquer to
prevent rust. The rest of the specimen's surface is dull and uneven and has a
dark brown coloration and a dull luster. There is a small patch of a
pale-colored material present in one area that has been rust-stained, but it is
nearly impossible to discern the Iron from the basalt host, except on the cut
surface. "... from 
<http://mineral.galleries.com/minerals/elements/iron/iron.htm>

"Terrestrial Iron-nickel is found sparingly in only a few localities; the most
famous are Kassel, Germany, the Kola Peninsula, Russia, and Disco Island (also
known as Qeqertarsuaq), Greenland, where the Iron/Iron-nickel was once thought
to be of alien origin. Small waterworn nuggets were found in the Fraser River,
near Lillooet, British Columbia, Canada, and in the Gorge river, New Zealand.
Terrestrial Iron/Iron-nickel was also found in Josephine Co., Oregon; Smith
River, Del Norte Co., California; Cameron, Clinton Co., Missouri; and St.
Josephs island in Lake Huron." from   
<http://www.minerals.net/mineral/elements/iron/iron.htm>

Regards,
Elton Jones

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